Tempo Mapping

Or beat mapping etc.
Ok probably this is a dumb question but I googled but found nothing.
If I go to project properties - ruler, I can set the bpm for the entire project but if I have a song with different bpm, how can I set those different bpm to the ruler to make grid matches that song bpm changes?
I hope my english was clear enough.
Thanks.

You need to do this before you drop the audio file into the project. Also the audio file needs to have ACID metadata in it or else Vegas won't know what BPM it uses. This works great with ACID Loops. If you want to use an entire song, you'll need to Beatmap it in ACID first.

I guess I wasn't clear enough.
John I want to set different bpms to the ruler and not only one for the entire project.
I don't want Vegas to know/follows audio file bpm, I want to set it manually.
As an example, in pro tools song bar 1 = 120 bpms, in bar 60 it changes to 80 bpms, so I can set any bpm I want to each bar, I just need to do that with vegas, let's say measure 1 = 120 bpms, measure 60 = 80 bpms.
Can I do that or vegas ruler have only one bpm to the entire project?